Calcutta: The city's annual average air pollution level is more than double the national limit and still rising in most parts of the city, a recently published report of the West Bengal Pollution Control Board has shown.

The report, a copy of which is with Metro, reveals that Calcutta's average PM10 pollutant value was 123.6 micrograms per cubic metre from April 2016 to March 2017 - more than double the national annual limit of 60 micrograms. PM10 is the fine particulate matter which, either individually or together with other toxic pollutants, can reach the respiratory system and cause pulmonary disorders, cardiac problems and even cancer.

The PM10 level was found to be much higher than national limits in all 17 measuring points in the city; the Hyde Road area being the worst offender at 154.4 micrograms. A close second was the Dunlop area with 152.2 micrograms, followed by the Moulali crossing with 148.9 micrograms. Rajarhat emerged as the cleanest with 86.8 micrograms.

A comparison of the pollution levels at nine locations in the city between April 2014 and March 2017 revealed an upward trend. The pollution count at Dunlop has increased from 136.5 to 152.2 micrograms, at Ultadanga from 119.5 to 134 and at Baishnabghata from 95.3 to 106.5 micrograms.

"There has been no effort by the environment department , the state pollution control board or the transport department to check pollution from vehicles or construction," environment activist Subhas Datta said.

Emission activist Somendra Mohon Ghosh pointed out that all the pollution measuring points are near busy traffic junctions, thus underlining the impact of vehicles on air.

A pollution control board official shifted the blame on the transport department for not removing polluting vehicles and the civic body for not taking steps against constructional pollution.